Monitoring and controlling the transit of people and/or vehicles in urban environments has currently become an issue of crucial importance to municipal and urban authorities. This monitoring does not only affect the transit of automobiles in the streets of a city, at certain points where traffic jams or dense traffic can occur, but also affects the deployment of traffic agents, cleaning services and other services during the daily life of the city. This also affects the displacement of people in large groupings and events or in their daily travels to their workplace.
Up to now, vehicle traffic was monitored practically in a statistical manner, using devices to count the vehicles that travel on a street during a certain period of time, such as car counter cables in the pavement, radar devices of video-surveillance cameras. After gathering the data at different points in the city, a crossed statistical analysis is performed with the position information of the measurement points. However, this information is confusing, as it does not consider the variation of vehicle flow rates during rush hours or on different days of the week (vehicles are often counted during one or two days to obtain a sufficient reliability of the sample), and results are obtained at a time that is too late for municipal authorities to make immediate or short-term decisions.
On another hand, controlling transit of people is more difficult, and is generally performed by installing turnstiles in office buildings or by approximate head counts using video and photographic cameras. However, the results obtained are highly localised and can vary considerably depending on the time and conditions of the sample.
The Traffic Measurement System (TMS) of the company Intellione is known, which uses the signal from mobile telephones to position people and vehicles in motion. Considering that in modern cities it is common for a large percentage of people to carry mobile telephones that are turned on during their daily activities, the communication signal of this telephone positions the person, whether moving in a vehicle or walking. Thus, the TMS system allows knowing the movement of people using the mobile telephony antenna network of the operators present in a city or urban area. This information can be processed in real time and is apparently reliable.
However, it has certain drawbacks. Firstly, the telephones must be positioned by triangulating antennas, as the coverage of an antenna can be quite large (up to several kilometers), so that it is harder to determine whether the location is a given street or an adjacent one. Secondly, the problem also exists that the antennas are positioned according to the coverage needs of the telephony service, so that they cannot provide an optimised distribution for studying traffic in a specific area, and its use is very difficult inside a building or a medium or small-sized installation. Thirdly, there is the problem of confidentiality, as the mobile telephone identifiers leave the network of the telephone operator in order to be processed, so that there is a risk of violating personal privacy.